Applicant has invented a new roof deck covering system as set forth in U.S. Pat. No. 4,926,596 and has also invented perimeter securement assemblies for securing the roof deck covering system shown in that patent. These are set forth in U.S. Pat. Nos. 4,912,900 and 5,025,604.
An important advantage of these securement systems involves the fact that the membrane covering on the roof is not punctured in securing it over the roof deck. Applicant has improved on these securement systems in two ways. Applicant has found that it is preferable in extremely large roof systems to be able to secure the membrane and the apertured overlay in areas of the roof other than at the periphery and around roof top units. Applicant has also found that it is desirable in the construction of a roof deck covering system of his type to be able to secure the membrane independently of securing the overlay.